LaLiga's request to postpone the upcoming match between Sevilla and Barcelona due to player involvement in South American World Cup qualifiers has been dismissed by the Royal Spanish Football Federation (RFEF), but a "challenge" will be lodged.

An appeal was issued by LaLiga to the Court of Arbitration for Sport (CAS) against the decision taken by FIFA to put in place a two-day extension to the CONMEBOL calendar for fixtures in September and October, a move made amid the complications caused by the coronavirus pandemic.

Due to strict rules that would require players to quarantine for 10 days upon their return, England's Premier League refused to release nearly 60 players travelling to 26 countries on the United Kingdom's red list due to COVID-19.

LaLiga announced support to those clubs in Spain that opted not to let individuals travel to play for South American nations in upcoming qualifiers. A total of 25 players from 13 different teams were due to be involved.

The organisation also filed a lawsuit against FIFA in the Swiss courts for infraction of competition rules, adding that domestic leagues had already accepted a new window in January 2022 to accommodate matches disrupted by the global pandemic.

However, CAS denied the interim measures put forward, meaning players would have to be released, and LaLiga responded by asking for two matches – Sevilla v Barcelona and Villarreal v Deportivo Alaves on September 11 – be postponed due to players only arriving back in Spain earlier that day.

While the RFEF has rejected the request, LaLiga insists it will continue to fight for those postponements, adamant the decision "is not in accordance with the law".

A statement read: "LaLiga expresses its absolute disagreement with the resolution of the president of the Competition Committee, issued by delegation of the president of the RFEF, to reject the postponement requests submitted by both Villarreal – with respect to the Villarreal v Deportivo Alaves match set for Saturday, September 11 at 18:30 – and Sevilla – for the Sevilla v Barcelona match set for Saturday, September 11 at 21:00 – and by LaLiga, organiser of this competition.

"The reason for these requests is to be able to maintain the integrity of the competition as a consequence of the extension of the FIFA period in September (CONMEBOL confederation) established by circular 1776 of August 13, setting the end of said period on Thursday, September 9 (early morning on Friday the 10th in Europe, with many players landing in Spain on Saturday morning and having to play games hours later).

"Finally, these requests have been rejected as it is considered, inexplicably, that based on article 239 of the general regulations of the RFEF, the circumstances raised are not identified as a cause of force majeure, motivated by an unforeseeable circumstance such as the current one that goes beyond of the mere summons of the players in the manner established by the regulations.

"In this sense, with this resolution of the RFEF (FIFA representative in Spain), the approach made by FIFA itself to oppose the precautionary measure requested by LaLiga before the CAS is being contradicted, indicating that it was easier for LaLiga to postpone these matches than for FIFA to postpone those of the CONMEBOL qualifiers.

"For all these reasons, LaLiga will challenge the aforementioned resolution considering it is not in accordance with the law."